Anesthesiologists play a vital and expanding role in the practice of critical care medicine, uniquely positioned to bridge the operating room and the intensive care unit (ICU). Their expertise in physiology, pharmacology, resuscitation, and complex monitoring enables comprehensive management of critically ill patients with multiorgan dysfunction before, during, and after surgery. This chapter outlines the anesthesiologist’s contributions to critical care through clinical leadership, procedural proficiency, and interdisciplinary collaboration. Critical care anesthesiologists oversee advanced interventions such as airway management, mechanical ventilation, hemodynamic monitoring, and procedures including bronchoscopy, tracheostomy, and transesophageal echocardiography. Their role extends to quality improvement, protocol development, and implementation of standardized pathways that reduce length of stay and improve outcomes. This chapter also highlights anesthesiologists’ leadership in palliative care, sleep medicine, and delirium prevention, demonstrating the specialty’s holistic approach to critically ill patients. Beyond direct patient care, anesthesiologists serve as innovators in tele-critical care, simulation-based training, and systems integration, ensuring continuous coverage and efficiency across perioperative and critical care environments. By uniting technical expertise with empathy and systems-based practice, critical care anesthesiologists embody the essential perioperative physician—delivering continuity, safety, and value across the entire spectrum of acute care.